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Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material that can be used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases. Occurrence and composition In 2005, the United States of America was the largest producer of fuller's earth with almost 70% world share followed at a distance by Japan and Mexico, reports the British Geological Survey. Fuller's earth usually has a high magnesium oxide content. In the United States, two varieties of fuller's earth are mined, mainly in the southeastern states. These comprise the minerals montmorillonite or palygorskite (attapulgite) or a mixture of the two; some of the other minerals that may be present in fuller's earth deposits are calcite, dolomite, and quartz. In England, fuller's earth occurs mainly in the Lower Greensand. It has also been mined in the Vale of White Horse, in Oxfordshire, England. The Combe Hay Mine was a fuller's earth mine operating to the south of Bath, Somerset until 1979. Other English sources include a mine near Redhill, Surrey (worked until 2000), and Woburn, Bedfordshire, where production ceased in 2004. In some countries, like the UK, calcium bentonite is known as fuller's earth, a term which is also used to refer to attapulgite, a mineralogically distinct clay mineral but exhibiting similar properties. Hills, cliffs and slopes containing fuller's earth can be unstable, since this material can be thixotropic, when saturated by heavy rainfall. Uses The name reflects the first use of the material. In past centuries, fullers kneaded fuller's earth and water into woollen cloth to absorb lanolin, oils, and other greasy impurities as part of the cloth finishing process. Similarly, it has been used as an ingredient in powdered, "dry" shampoos, such as the (no longer manufactured) Minipoo. Fuller's earth was also sold in pharmacies until recently for compressing pills and it is sometimes used by crane operators and their oilers to absorb grease and oil off the brake bands on the winches to make them function properly. It also finds use in special effects when simulating explosions. Fine-grained fuller's earth makes a much larger plume than ordinary dirt, suggesting a larger explosion and allowing a smaller, safer charge to be used. In addition, it can be used to artificially age costumes, such as jackets and shirts, to make them appear older and more worn in while remaining easy to remove from the article it is applied to. Important uses are in absorbents and filters. Because of this, it is used (with activated charcoal) in the treatment of paraquat overdose to prevent the progression to pulmonary fibrosis. Fuller's earth is also used by military and civil emergency service personnel to decontaminate the clothing and equipment of soldiers and CBRN (Chemical Biological Radiological Nuclear) responders who have been contaminated with chemical agents. Similarly, fuller's earth is sometimes found in cat litter and is also used by owners of chinchillas and degus to give the animals a dust bath. In fly fishing, a mixture of fuller's earth and detergent can be used to prevent undesirable flotation of a greasy fly fishing leader (the fine fishing line attached to the fly). The aim is to prevent the fish seeing it on the surface thereby becoming frightened off or "spooked". In skin care, fuller's earth has been used as a facial mask because of its ability to absorb impurities. It is gentle and can even be used daily by some people. It is used in the treatment of severe diaper rash in babies. Fuller's Earth can also be used to treat burn or acne scars by making a mixture of lemon juice, rose water, and fuller's earth. It is a less popular home remedy for scar removal, but it works. Literary References Fuller's earth plays prominently in the Sherlock Holmes story "The Adventure of the Engineer's Thumb", in which a young hydraulic engineer is lured to a small estate ostensibly to investigate a piece of machinery involved in the excavation of the material. See also * Bentonite * Sepiolite * Medicinal clay Sinónimos Fullers Clay, Oil Absorption Clay, Earth Clay, Bleaching Clay and Whitening Clay. #Bentonita,Compuesta básicamente por Montmorillonita. #Tierra sacamanchas.Diccionario español e ingles. Autor Giuseppe Baretti, Giuseppe Marco Antonio Baretti, Jean-Baptiste Delamollière, Étienne Piestre #Tierra de Fuller. #Esmectita. Bleicherde *British Geological Survey, Mineral Fact Sheet: Fuller's Earth http://www.bgs.ac.uk/downloads/start.cfm?id=1358 (accessed 7 August 2009). * * Oxford English Dictionary, Second Edition. Oxford: Oxford U P, 1989. Cited Further reading *Brady, G.S., Clauser, H.R., & Vaccari, J.A. (2002). Materials handbook. (15th ed.) New York: McGraw-Hill. *Hosterman, J.W. and S.H. Patterson. (1992). Bentonite and Fuller's earth resources of the United States Geological Survey Professional Paper 1522. Washington, D.C.: United States Government Printing Office. Categoría:Diccionario de cerámica inglés - español: F Categoría:Minerals Categoría:Types of soil Categoría:Medicinal clay Categoría:Arcillas Categoría:Glosario Categoría:Diccionario F